本研究使用滑石(Talc)、高嶺石(Kaolinite)及4種不同粒徑α-氧化鋁粉末，以固態反應法合成堇青石(Cordierite)。原料粉末經混合、烘乾、研磨過篩及壓錠成型後，獲得4組混有不同粒徑α-氧化鋁粉末之樣品。經熱處理起始樣品，觀察不同粒徑氧化鋁粉末對合成堇青石過程中反應機制之變化，及對合成堇青石產品性質之影響。
研究結果顯示：改變氧化鋁原料粒徑主要影響氧化鋁參與反應之溫度。細粒徑氧化鋁(< 200nm)可低於1200℃與頑火輝石(Protoenstatite，由滑石分解生成)反應，大量生成鎂鋁尖晶石(Spinel)。生成之鎂鋁尖晶石於1350℃與系統中之二氧化矽反應生成α-堇青石；粗粒徑氧化鋁(> 200nm)則需高於1200℃才參與反應，與頑火輝石生成β-堇青石。之後β-堇青石於1300℃以上相轉換成α-堇青石。若在1350℃以上尚未反應完之氧化鋁，則與頑火輝石及二氧化矽反應生成α-堇青石。
將混有4種粒徑氧化鋁之樣品經熱處理後，進行相鑑定及熱膨脹係數量測。發現以相同熱處理條件下，混有粗粒徑氧化鋁樣品之過渡相含量及熱膨脹係數，明顯高於混有細粒徑氧化鋁樣品。實驗最後使用100nm氧化鋁粉末合成出高純度、低熱膨脹係數堇青石樣品，測得由室溫至900℃之熱膨脹係數為1.17 × 10-6 m/m℃。

This study we used talc, kaolinite and four different particle size α-alumina powders to synthesize cordierite by solid-state reaction method. After the raw material powders were mixed, dried, sieved, and pressed into ingot, four samples with different α-alumina particle size were obtained. After heating treatment of samples, the influence between the different particle size α-alumina to synthesis mechanism, and properties of the synthetic cordierite products were observed.
The results indicate that the changing of the particle size of alumina powders affect the reaction temperature. By reacting with protoenstatite (from decomposition of talc), fine particle size of alumina (<200nm) can yield a large amount of spinel at the temperature lower than 1200℃. After that spinel reacted with silica to synthesize α-cordierite at 1350℃. Coarse alumina (> 200nm) needs even more higher temperature than 1200℃ in order to react with protoenstatite for yielding β-cordierite. At the temperature higher than 1300℃, β-cordierite will then transfer into α-cordierite. At the temperature higher than 1350℃, the unreacted alumina will become α-cordierite by reacting with protoenstatite and silica.
After heat treatment, four samples with different α-alumina particle size were phase identified and measured their coefficients of thermal expansion (C.T.E). The result indicate that with the same heat treatment conditions, samples mixed with the coarse alumina have higher transition phase content, and their C.T.E was significantly higher than mixed with fine alumina samples. At the end of this experiment, the particle of 100nm alumina powder was used to synthesize high cordierite content sample. The C.T.E is 1.17 × 10-6 m/m℃ from room temperature to 900 ℃.

[1] E.M. Levin, Phase diagrams for ceramicists, The American Ceramic Society, Inc.. 1964.
[2] Malcolm D. Glendenning and William E. Lee, “Microstructural development on crystallizing hot-pressed pellets of cordierite melt-derived glass containing B2O3 and P2O5,” Journal of the American Ceramic Society, 79, 705-13, 1996.
[3] M. D. Karkhanavala and F. A. Hummel, “The polymorphism of cordierite,” Journal of the American Ceramic Society, 36, 389-392, 1953.
[4] G. V. Gibbs, “The polymorphism of cordierite I: The crystal structure of low cordierite ,” The American Mineralogist, 51, 1068- 1087, 1966.
[5] E. P. Meagher and G. V. Gibbs, “The polymorphism of cordierite II: The crystal structure indialite ,” Canadidn Mineralogist, 15, 43-49, 1977.
[6] Zagorka Acimovic, Ljubica Pavlovic, Ljiljana Trumbulovic, Ljubisa Andric and Milan Stamatovic, “Synthesis and characterization of the cordierite ceramics from nonstandard raw materials for application in foundry,” Materials Letters, 57, 2651– 2656, 2003.
[7] Cristina Ghitulica , Ecaterina Andronescu, Oana Nicola, A. Dicea and Mihaela Birsan, “Preparation and characterization of cordierite powders,” Journal of the European Ceramic Society, 27, 711–713, 2007.
[8] Shu-Ming Wanga, Feng-Hua Kuanga, Qing-Zhi Yana, Chang-Chun Gea and Long-Hao Qi, “Crystallization and infrared radiation properties of iron ion doped cordierite glass-ceramics,” Journal of Alloys and Compounds, 509, 2819–2823, 2011.
[9] Andrew Putnis, ”Introduction to mineral science,” Cambridge University press, 1992.
[10] M. F. Hochella, Jr., and G. E. Brown, Jr., “Structural mechanisms of anomalous thermal expansion of cordierite-beryl and other framework silicates,” Journal of the American Ceramic Society, 69, 13-18, 1986.
[11] Hiroyuki Ikawa, Tadashi Otagiri,” Osamu Imai,” Masaharu Suzuki, Kazuyori Urabe and Shigekazu Udagawa, “Crystal Structures and Mechanism of Thermal Expansion of High Cordierite and Its Solid Solutions,” Journal of the American Ceramic Society, 69, 492-98, 1986.
[12] John Faber, Jr., and R. L. Hitterman ,“Structural Aspects of the Lattice Thermal Expansion of Hexagonal Cordierite,” Journal of the American Ceramic Society, 70, 175-82, 1987.
[13] Akiho Miyashiro, “Cordierite-indialite reations,” Journal of the American Ceramic Society, 255, 43-62, 1957.
[14] 黃忠良 譯，工程陶瓷，復漢出版社，1985。
[15] I. M. Lachman, R. D. Bagley, and R. M. Lewis, “Thermal expansion of extruded cordierite ceramic,“Ceramic Bulletin, 60, 202-205, 1981.
[16] Zhu Kai, Yang DaoYuan, Wu Juan and Zhang Rui, “Synthesis of Cordierite with Low Thermal Expansion Coefficient,” Advanced Materials Research, 105-106, 802-804, 2010.
[17] R. Goren, C. Ozgur and H. Gocmez, “The preparation of cordierite from talc, fly ash, fused silica and alumina mixtures,” Ceramics International, 32, 53–56, 2006.
[18] Yuichi Kobayashi, Katsuhiro Sumi and Etsuro Kato, “Preparation of dense cordierite ceramics from magnesium compounds and kaolinite without additives,” Ceramics International, 26,739-743, 2000.
[19] Ulagaraj Selvaraj, Sridhar Komarneni, and Rustum Roy, “Synthesis of Glass-like Cordierite from Metal Alkoxides and Characterization by 27Al and 29Si MASNMR,” Journal of the American Ceramic Society, 73, 3663-3669, 1990.
[20] 鄭淼晶，以溶膠凝膠法製備菫青石粉末及其燒結體之性質研究，國立成功大學資源工程所碩士論文，中華民國九十三年。
[21] Johar Banjuraizah, Hasmaliza Mohamad and Zainal Arifin Ahmad, “Crystal structure of single phase and low sintering temperature of α-cordierite synthesized from talc and kaolin,” Journal of Alloys and Compounds, 482, 429–436, 2009.
[22] M.A. Camerucci and A.L. Cavalieri, “Wetting and penetration of cordierite and mullite materials by non-stoichiometric cordierite liquids,” Ceramics International, 34, 1753–1762, 2008.
[23] J.R. Gonza´lez-Velasco, R. Ferret, R. Lo´pez-Fonseca and M.A. Gutie´rrez-Ortiz, “Influence of particle size distribution of precursor oxides on the synthesis of cordierite by solid-state reaction,” Powder Technology , 153, 34–42, 2005.
[24] Maria Teresa Buscaglia, Marta Bassoli, and Vincenzo Buscaglia, “Solid-state synthesis of ultrafine BaTiO3 powders from nanocrystalline BaCO3 and TiO2,” Journal of the American Ceramic Society, 88, 2374–2379, 2005.
[25] J.M. Rivas Mercury, A.H. De Aza and P. Pena, “Synthesis of CaAl2O4 from powders Particle size effect,” Journal of the European Ceramic Society, 25, 3269–3279, 2005.
[26] S. Shimada, K. Soejima and T. Ishii, “Influence of particle size of α-Fe2O3 on the formation of ZnFe2O4 and the implications of a characteristic surface texture of the ferrite phase formed on α-Fe2O3 particles,” Reactivity of Solids, 8, 51-61, 1990.
[27] 賴佳芸，氧化釔粉末粒徑對YAG生成活化能影響，國立成功大學資源工程研究所碩士論文，中華民國九十七年。
[28] W. D. Kingery, Harvey Kent Bowen and Donald Robert Uhlmann, Introduction to ceramics, Wiley, New York, 1976.
[29] 汪建民，栗愛綱編，精密陶瓷特性及檢測分析，工業技術研究院工業材料研究所編印，中華民國77年。
[30] Johar Banjuraizah, Hasmaliza Mohamad and Zainal Arifin Ahmad, “Effect of excess MgO mole ratio in a stoichiometric cordierite (2MgO‧2Al2O3‧5SiO2) composition on the phase transformation and crystallization behavior of magnesium aluminum silicate phases,” International Journal of Applied Ceramic Technology, 8, 637–645, 2011.
[31] Matsuhisa, “Cordierite ceramic,” United States Patent: 4280845, 1981.
[32] Hamanaka,“Method of producing a cordierite honeycombs structural body,” United States Patent: 5030398, 1991.
[33] Akshoy Kumar Chakravorty and Dilip Kumar Ghosh, “Kaolinite-Mullite Reaction Series: The Development and Significance of a Binary Aluminosilicate Phase,” Journal of the American Ceramic Society, 74, 1401-1406, 1991.
[34] J.M. Benito, X. Turrillas, G.J. Cuello, A.H. De Aza, S. De Aza and M.A. Rodríguez, “Cordierite synthesis. A time-resolved neutron diffraction study,” Journal of the European Ceramic Society, 32, 371–379, 2012.
[35] J.R. Gonza´lez-Velasco, R. Ferret, R. Lo´pez-Fonseca and M.A. Gutie´rrez-Ortiz,” Synthesis of cordierite monolithic honeycomb by solid state reaction of precursor oxides”, Journal of Materials Science , 34, 1999 – 2002, 1999.
[36] J. Setina, “Preparation of synthetic cordierite by solide-state-reaction with addition of dolomite,” Advances in Science and Technology, 45, 77-82, 2006.
[37] Marek Wesolowski, “Thermal decomposition of talc a review,” Thermochimica Acta, 78, 395-421, 1984.
[38] T. Ebadzadeh and W. E. Lee, “Processing microstructure property relations in mullite-cordierite composites,” Journal of the European Ceramic Society, 18, 837-848, 1998.
[39] S. Kumar, K. K. Singh and P. Ramachandrarao, “Synthesis of cordierite from fly ash and its refractory properties,” Journal of Materials Science Letters, 19, 1263 – 1265, 2000.
[40]R. Bejjaoui, A. Benhammou, L. Nibou, B. Tanouti, J. P. Bonnet, A. Yaacoubi and A. Ammar, “Synthesis and characterization of cordierite ceramic from Moroccan stevensite and andalusite,” Applied Clay Science, 49, 336–340, 2010.
[41] R. Goren, C. Ozgur and H. Gocmez, “Synthesis of cordierite powder from talc, diatomite and alumina,” Ceramics International, 32, 407–409, 2006.